syzbot
stack segment fault in bpf_redirect
Status: closed as invalid on 2026/08/26 17:27
Subsystems:
bpf
net
Labels:
prio:high
[Documentation on labels]
First crash: 194d, last: 54d
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Last patch testing requests (11)
Sample crash report:
syzkaller0: entered promiscuous mode
syzkaller0: entered allmulticast mode
Oops: stack segment: 0000 [#1] SMP KASAN PTI
CPU: 1 UID: 0 PID: 5988 Comm: syz.0.17 Not tainted syzkaller #0 PREEMPT(full)
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 02/12/2026
RIP: 0010:bpf_net_ctx_get_ri include/linux/filter.h:820 [inline]
RIP: 0010:____bpf_redirect net/core/filter.c:2545 [inline]
RIP: 0010:bpf_redirect+0x58/0x170 net/core/filter.c:2543
Code: 81 c7 30 18 00 00 4c 89 f8 48 c1 e8 03 42 80 3c 28 00 74 08 4c 89 ff e8 b6 d8 b3 f8 4d 8b 3f 4d 8d 67 38 4c 89 e5 48 c1 ed 03 <42> 0f b6 44 2d 00 84 c0 0f 85 b9 00 00 00 41 8b 1c 24 89 de 83 e6
RSP: 0018:ffffc90003017078 EFLAGS: 00010202
RAX: 1ffff11005f93306 RBX: dffffc0000000000 RCX: ffff88802fc98000
RDX: 0000000000000000 RSI: 00000080ffffffff RDI: ffff88802a299b40
RBP: 0000000000000007 R08: 1ffff11005453382 R09: 1ffff11005453376
R10: ffffc90003017320 R11: ffffffffa0205108 R12: 0000000000000038
R13: dffffc0000000000 R14: 00000080ffffffff R15: 0000000000000000
FS: 000055555d9ee500(0000) GS:ffff8881255b0000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000200000002280 CR3: 000000007e456000 CR4: 00000000003526f0
Call Trace:
<TASK>
bpf_prog_6338e008a91e2d10+0x23/0x29
bpf_dispatcher_nop_func include/linux/bpf.h:1402 [inline]
__bpf_prog_run include/linux/filter.h:723 [inline]
bpf_prog_run include/linux/filter.h:730 [inline]
bpf_prog_run_data_pointers+0x19d/0x340 include/linux/filter.h:918
cls_bpf_classify+0x25b/0xad0 net/sched/cls_bpf.c:103
tc_classify include/net/tc_wrapper.h:197 [inline]
__tcf_classify net/sched/cls_api.c:1764 [inline]
tcf_classify+0x4cf/0x1130 net/sched/cls_api.c:1860
drr_classify net/sched/sch_drr.c:317 [inline]
drr_enqueue+0x2d4/0x9d0 net/sched/sch_drr.c:346
dev_qdisc_enqueue+0x4e/0x240 net/core/dev.c:4144
__dev_xmit_skb net/core/dev.c:4259 [inline]
__dev_queue_xmit+0x1ae1/0x3850 net/core/dev.c:4795
packet_snd net/packet/af_packet.c:3077 [inline]
packet_sendmsg+0x3eb6/0x50f0 net/packet/af_packet.c:3109
sock_sendmsg_nosec net/socket.c:727 [inline]
__sock_sendmsg net/socket.c:742 [inline]
____sys_sendmsg+0xa68/0xad0 net/socket.c:2592
___sys_sendmsg+0x2a5/0x360 net/socket.c:2646
__sys_sendmsg net/socket.c:2678 [inline]
__do_sys_sendmsg net/socket.c:2683 [inline]
__se_sys_sendmsg net/socket.c:2681 [inline]
__x64_sys_sendmsg+0x1bd/0x2a0 net/socket.c:2681
do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
do_syscall_64+0x14d/0xf80 arch/x86/entry/syscall_64.c:94
entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7efe1359bf79
Code: ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 44 00 00 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 c7 c1 e8 ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007ffdb2b92be8 EFLAGS: 00000246 ORIG_RAX: 000000000000002e
RAX: ffffffffffffffda RBX: 00007efe13815fa0 RCX: 00007efe1359bf79
RDX: 0000000000000005 RSI: 0000200000000280 RDI: 0000000000000007
RBP: 00007efe136327e0 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007efe13815fac R14: 00007efe13815fa0 R15: 00007efe13815fa0
</TASK>
Modules linked in:
---[ end trace 0000000000000000 ]---
RIP: 0010:bpf_net_ctx_get_ri include/linux/filter.h:820 [inline]
RIP: 0010:____bpf_redirect net/core/filter.c:2545 [inline]
RIP: 0010:bpf_redirect+0x58/0x170 net/core/filter.c:2543
Code: 81 c7 30 18 00 00 4c 89 f8 48 c1 e8 03 42 80 3c 28 00 74 08 4c 89 ff e8 b6 d8 b3 f8 4d 8b 3f 4d 8d 67 38 4c 89 e5 48 c1 ed 03 <42> 0f b6 44 2d 00 84 c0 0f 85 b9 00 00 00 41 8b 1c 24 89 de 83 e6
RSP: 0018:ffffc90003017078 EFLAGS: 00010202
RAX: 1ffff11005f93306 RBX: dffffc0000000000 RCX: ffff88802fc98000
RDX: 0000000000000000 RSI: 00000080ffffffff RDI: ffff88802a299b40
RBP: 0000000000000007 R08: 1ffff11005453382 R09: 1ffff11005453376
R10: ffffc90003017320 R11: ffffffffa0205108 R12: 0000000000000038
R13: dffffc0000000000 R14: 00000080ffffffff R15: 0000000000000000
FS: 000055555d9ee500(0000) GS:ffff8881255b0000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000200000002280 CR3: 000000007e456000 CR4: 00000000003526f0
----------------
Code disassembly (best guess):
0: 81 c7 30 18 00 00 add $0x1830,%edi
6: 4c 89 f8 mov %r15,%rax
9: 48 c1 e8 03 shr $0x3,%rax
d: 42 80 3c 28 00 cmpb $0x0,(%rax,%r13,1)
12: 74 08 je 0x1c
14: 4c 89 ff mov %r15,%rdi
17: e8 b6 d8 b3 f8 call 0xf8b3d8d2
1c: 4d 8b 3f mov (%r15),%r15
1f: 4d 8d 67 38 lea 0x38(%r15),%r12
23: 4c 89 e5 mov %r12,%rbp
26: 48 c1 ed 03 shr $0x3,%rbp
* 2a: 42 0f b6 44 2d 00 movzbl 0x0(%rbp,%r13,1),%eax <-- trapping instruction
30: 84 c0 test %al,%al
32: 0f 85 b9 00 00 00 jne 0xf1
38: 41 8b 1c 24 mov (%r12),%ebx
3c: 89 de mov %ebx,%esi
3e: 83 .byte 0x83
3f: e6 .byte 0xe6
* Struck through repros no longer work on HEAD.